Should the Changan Yidong Plus use 92 or 95 octane gasoline?

[VanKing]

According to the official vehicle manual recommendation, the Changan Yidong Plus should use 92 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual for the Changan Yidong Plus, you can also find it on the fuel tank cap, which will also be marked. Usually, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should choose 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should opt for 95 octane gasoline. However, with the use of some new technologies nowadays, the gasoline grade cannot be solely determined by the compression ratio. A high compression ratio can also be tuned to use lower-grade gasoline. This is because, apart from the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline grade, the higher the octane number and the better the anti-knock performance. 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. If the Changan Yidong Plus occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower-grade gasoline, mistakenly using higher-grade gasoline will not cause damage, but the increase in octane number will change the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in poorer performance as experienced in real feedback. For vehicles recommended to use higher-grade gasoline, using lower-grade gasoline can cause engine knocking. Because the octane number is too low, the gasoline's ignition point decreases and may ignite prematurely during the compression stroke. If combustion occurs before the spark plug ignites during the compression stroke, resistance will arise during the upward stroke. This resistance makes the engine run very unstably. If it's mild knocking, it only increases noise without significant damage to the engine. However, if there is noticeable knocking, it indicates severe engine conditions. The vibration not only affects driving stability but also causes abnormal wear on the pistons and cylinders, and in severe cases, can lead to cylinder scoring.

[EvelynDella]

The Changan Yidong PLUS generally recommends using 92-octane gasoline, as clearly stated in the user manual. The engine was designed to be compatible with 92-octane fuel, which has moderate octane levels and sufficient anti-knock properties. Using 95-octane is unnecessary—it's more expensive and not worth the extra cost, with a price difference of several cents per liter, saving you at least a few hundred yuan annually. For my daily city commute, 92-octane ensures smooth engine performance and good fuel efficiency. If you frequently drive in high-temperature areas or mountainous regions, occasionally switching to 95-octane might make the ride slightly smoother, but there's no need to change your routine. The engine is tuned to avoid issues like carbon buildup or reduced lifespan from mixing fuel types, so sticking to one is best. Also, choose reputable gas stations to ensure fuel quality—don’t compromise with substandard fuel to save money. In short, the manual doesn’t lie: 92-octane is both economical and safe.

[KadenAnn]

I think using 92-octane gasoline for the Changan Eado PLUS is the most cost-effective choice. 95-octane is significantly more expensive without offering a noticeable performance boost, making it unnecessary to waste money. I've compared fuel tank data—the engine's compression ratio isn't high, so 92-octane's anti-knock properties are sufficient for most driving conditions. Whether idling in traffic with AC on or accelerating, 92-octane delivers ample power. On highways or long trips, 95-octane might offer slightly quicker throttle response, but the difference is too minor to justify the extra cost. The savings can instead fund better maintenance or higher-quality engine oil, which benefits the car more. Just be cautious about gas stations—avoid sketchy ones with cheap, low-grade fuel that harms engines. Since the first service, I've used only 92-octane; after 20,000 km, the engine runs flawlessly, proving its refined design. Simply put, 92-octane saves money, hassle, and performs perfectly.

[BenjaminRose]

From a technical perspective, the Changan Eado PLUS is suitable for 92-octane gasoline. The octane rating determines the anti-knock performance, and the 92-octane grade matches the engine's compression ratio, ensuring combustion efficiency. Using 95-octane incurs additional costs with limited engine adaptability, and frequent switching between grades may lead to uneven combustion or carbon deposits. Manufacturer tests recommend 92-octane as optimal for daily driving. In special conditions like high-temperature environments, 95-octane can be considered but is not mandatory. Maintaining consistent fuel quality extends engine lifespan.